In some inkjet type dispensers, resistors heat ink and other liquids to eject drops of the liquid from tiny dispensing chambers toward a target. An inkjet printhead may include hundreds or thousands of resistors. Resistors are turned on and off selectively to dispense drops of liquid on to (or in to) the target as desired, for example to form a printed image on a sheet of paper. The resistors are usually covered by a tough material that protects the resistors from the harsh environment inside the dispensing chambers. These protective coverings are commonly referred to as “passivation” structures.
The same part numbers designate the same or similar parts throughout the figures. The figures are not necessarily to scale.